solar cover

does it hurt the water if you leave your solar cover on for days at a time . someone told me that you have to take it off during the day or you're water will start to go bad.

one other question. i know the cover keeps the water from losing heat at night but what about during a hot day . will it warm up the water faster with it on or offf?


thanks

If the water under the cover is properly maintained it will be fine--I do it ALL the time.

Covers can help heat and not help. The biggest help is insulating, but clear cover allow sunlight to pass through and heat the water. Opaque ones transmit the heat to the water.

I'm not sure what the difference is, Carl. If a clear cover lets the sun's heat in, will it let the pool heat out? Does a dark cover merely keep the heat in without allowing any gain?

Thanks.

You will probably get the most heat gain if the sun rays reach the bottom of the pool - that way as the water from the bottom warms, it will rise and you end up distributing the heat throughout the pool. A clear cover will allow this (as will leaving the cover off). If you have an opaque cover, it will transfer the sun's heat to the first few inches near the cover and the pump will move the warm water around so it should still mix in.

Any cover should be able to act as an insulating barrier to keep the heat in at night so I don't think the color will matter in that regard.

Peter

The biggest problem I have with leaving the cover on during the day is that the skimmers don't work, so I get a lot of bugs and debris in the pool. I usually roll it up in the morning.

If you go play with the swimming pool energy calculator provided by the Department of Energy (your tax dollars at work, find it through Google), you will learn that a solar cover really doesn't do that much in terms of "insulating" the pool at night. How it helps is in preventing evaporation of the pool water - around 90 percent of the energy lost is due to evaporation. That's why it doesn't make sense to insulate the sides of an AG pool - free or mildly forced convection can't compete with the evaportation. Next time you swim after the cover has been off for while at night, notice that the top couple of inches are much cooler than the rest of the pool, even colder than the outside air. That's Thermodynamics in Action!

And yes, I have a Ph.D. in Mechanical Engineering, so I'm kind of a geek about this sort of stuff. My apologies if your eyes are glazed over!

Doug